This invention relates to a method and apparatus for optimizing the speed of a glassware forming process.
Glassware forming systems include a forehearth which contains a channel of molten glass from which a feeder bowl mechanism extends. The feeder mechanism forms gobs of molten glass from the forehearth and a distributor mechanism distributes the gobs to each of a plurality of blank molds in an I.S. machine. The gobs of molten glass are processed by the I.S. machine to form containers which were then placed on a takeout conveyor and carried to a lehr where the containers are annealed. In the past, the plunger in the feeder mechanism, the shears for cutting the molten glass to form gobs, the distributor mechanism and the I.S. machine were all operated by a motor drive system whose speed varied depending upon the type of glass being formed. Thus, small containers, such as baby food jars, are formed at a relatively rapid rate whereas large containers, such as gallon jugs, are formed at a relatively slow rate. Since the process of converting a gob of molten glass to a container is, in essence, a thermodynamic process of removing heat from the gob while shaping same in a controlled fashion, the speed of the glassware forming process is, in large part, dependent upon the ability of the I.S. machine to remove heat from the glass in a controlled manner. In the past, the speed at which glassware containers were formed was determined by an operator who depended upon his skill and training to determine the best speed for forming various types of glassware containers.
More recently, as disclosed in the copending U.S. patent application of Wood, Ser. No. 281,565, entitled "Programmable Speed Controller" and assigned to the common assignee herewith, a system is disclosed for controlling the speed of an I.S. machine, the gob distributor and the feeder mechanism by means of a direct computer control. This system has the advantage of providing more positive control of the glassware forming process and facilitates the control of the process. However, the speed with which the glassware forming process operates again is determined by, and hence is dependent upon, the training and experience of an operator.
There accordingly is a need in the art for an improved method and apparatus for controlling and optimizing the speed at which glassware containers are formed.